The bi-level optimisation process is demanding in terms of GPU memory and computation. Partial channel connections [1]} were proposed as a solution to improve efficiency, reducing demands on both computation and memory. A binary masking operator \(\mathbf {S}^{\left(i,j\right)}\)  is used in partially connected (PC) DARTS in order to reduce the complexity of (REF ). The number of active channels in \(\mathbf {x}^{\left(i\right)}\)  is reduced through either selection (marked as \(\mathbf {S}^{\left(i,j\right)}=1\) ) or masking (marked as \(\mathbf {S}^{\left(i,j\right)}=0\) ) according to:
\(\bar{o}^{\left(i,j\right)}\left(\mathbf {x}^{\left(i\right)}\right) =\sum _{o \in \mathcal {O}} \frac{\exp {\left(\alpha _o^{\left(i,j\right)}\right)}}{\sum _{o^{\prime } \in \mathcal {O}} \exp {\left(\alpha _{o^{\prime }}^{\left(i,j\right)}\right)}}\, o\left(\mathbf {S}^{\left(i,j\right)} \odot \mathbf {x}^{\left(i\right)}\right)\\ + \left(1 - \mathbf {S}^{\left(i,j\right)}\right) \odot \mathbf {x}^{\left(i\right)}\) 
